Tuesday, September 21, 2010

jupiter's opposition, the equinox, and the full moon

tomorrow is the equinox, which means that the hours of daylight and darkness are very nearly equal. welcome to a new season (and hopefully lots of colorful leaves in the trees in ohio when i visit next week!).

the next few evenings will also be lovely for looking towards the sky. maybe you've noticed an incredibly bright object shining in eastern skies over the last couple months? that's the planet jupiter. wednesday, the harvest moon will be full, and the brightly shining, nearby jupiter will be hanging in the sky just below it.

last night jupiter was at opposition (when the earth passes between the sun and jupiter), constituting jupiter's closest physical approach to us on earth! every earth year, jupiter goes thru an opposition position, but its physically a little closer or farther each time. this time, it happens to be closer than it has been since 1963 and closer than it will be again until the year 2022, and as such, it looks especially bright in our sky! the jovian giant is about 368 million miles away.

you can see below how the planets of our solar system are currently aligned (the map is not to scale).

earth is just to the right of the sun, and you can see jupiter in a straight line farther out to the right. even farther out is the planet uranus. in fact, if you look to the upper left of jupiter in the (northern hemisphere's) sky with the aid of binoculars or a small telescope, you should easily be able to spot uranus, and maybe even the 4 galilean moons of jupiter! from the southern hemisphere, you'll find uranus to the lower left of jupiter.

be sure to go out, take a look, take a picture, and enjoy the changing of the seasons.